Hello!
So, to answer this question we need to note that quadruple = x4
25 (our initial count) x 4 = 100
100 (after one hour) x 4 = 400
400 (after two hours) x 4 = 1600
1600 (after three hours) x 4 = 6400
6400 (after four hours) x 4 = 25600
25600 (after five hours) x 4 = 102400
So to answer your question, after six hours, there will be 102,400 of that bacteria in the jar.
Hope this helps!